Two temperature refrigerator with forced air circulation



1958 J. M. MURPHY ET AL 2,859,595

TWO TEMPERATURE REFRIGERATOR WITH FORCED AIR CIRCULATION Filed March 25, 1954 5 Sheets-Sheet 1 INVENTORS John M. Mur by and By Leonard J. ann

Their Attorney Nov. 11, 1958 J. M. MURPHY ET AL Two TEMPERATURE REFRIGERATOR WITH FORCED AIR CIRCULATION 5 Sheets-Sheet 2 Filed March 25, 1954 A I/ 1/ I/ l 1 ,1 I v 3 v/ 9 u M/ I INVENTORS Murphy and By Leonard J. Mann John M.

Their Attorney TWO TEMPERATURE REFRIGERATOR WITH FORCED AIR CIRCULATION 3 Sheets-Sheet 3 Filed March 25, 1954 n 5 n m .n 0 0 N-M-G E M V u mM 3 .d r M .9 mm I JL Y B Their TWO TEMPERATURE REFRIGERATOR WITH FORCED AIR CIRCULATION John M. Murphy and Leonard J. Mann, Dayton, Ohio, assiguors to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application'March 25, 1954, Serial No. 418,668

5 Claims. (Cl. 62214) This invention relatesto .refrigerating apparatus and more particularly to an improved multiple compartment type of refrigerator.

The desirability, of providing food storage receptacles such as small shelves as well as hydrators on the door of a refrigerator has long ,been recognized but has presented problems which heretofore have notbeen properly solved. One of the problems is that of obtaining enough air circulation to properly refrigerate the foods stored on such shelves and in such hydrators. Another problem is that of providing hydrators of any appreciable size,.on the door which do not unduly interfere with the. foods stored on the main shelves within the refrigerator. It is an object of this invention to overcome these problems .in a simple and practical manner.

Still another object of this invention is to provide a hydrator which may be supported on the door and which folds down so as to serve as a rearranging shelf when' i the refrigerator door is in the open position.

Another object of this invention is to provide an improved arrangement of compartments which eliminates the need for a secondary refrigerating system.

A further object of this invention is to provide'an improved type of automatic defrosting arrangement in a refrigerator using forced air circulation over a portion of the evaporator. I

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly 7 shown.

. mounting for. the hydrator on the. door; and,

Figure 4 is a fragmentary sectional view taken substantially on line 4-4 .of Figure 2, showing the one evaporator in the air flue and schematically showing the refrigerant circuit.

'Referring now to the drawing wherein a preferred .embodiment of the invention has been shown, reference numeral 10 generally designates a household refrigerator having a'motor-compressor compartment 12, a frozen -food-storage compartment 14, a main food storage compartment 16for storing unfrozen foods and a hydrator 18 pivotally supported on the main refrigerator door 20. The. refrigerator comprises the usual sheet metal outer shell 22 which serves to support a pair of inner liner eleiments :24 and 26Whi'ch form the frozen food compartment and the unfrozen food storage compartment respec- A tively. Suitable insulation 28 is provided between the outer shell 22 and the inner liners.

' The main door is provided with one or more shelves Unite Sttes atent- Patented Nov. :11, tees in vertical channels 35 carried bythe door whereby the hydrator can be lowered from a position up against the door as shown in Figures 2 and 3 to the position shown in Figure 1 or can be removed from its support. The hydrator is provided with a p-airof pivoted lids 37 which can be used as rearranging shelvesswhen the hydrator is in the position shown in Figure 1. Latch means 39 help to hold the hydrator up against the door.

It will be noted that. a clearance space 41 is provided between the hydrator 18 and the door which permits the passage of air therethrough so as to provide refrigeration to all portions, of the hydrator as well as to. permit the circulation of air past the shelves 30. It will be noted that the shelves 30 are also. spaced slightly from the door allowing the air to circulate into close contact with the foods stored on the shelves.

The refrigerating system which is used for cooling the food stored in the compartmentsl i, .16 and 18 consists of the usual motor-compressor unit 50 which is preferably of the hermetically sealed rotary type which isnow very well known. The compressed refrigerant leaving the compressor 50 flows into. the condenser '52 from whence the liquid refrigerant flows through a conventional :fixed restrictor type of pressure reducing device 54. Insofar as certain aspects of this invention are concernedany type of pressure reducing means may be used suchas an automatic expansion valve or a thermostatic expansion valve.

In the preferred embodiment of the invention,.a fixed restrictor is used and serves to convey liquefied refrigerant into a first primary evaporator 56 which is incorporated in the liner 24 of the frozen food compartment 14. After the evaporator 56 has been filled with liquid refrigerant the surplus refrigerant flows through an unrestricted passage.58 into a second primary. evaporator,-60; which is mounted in an air flue at the back of the compartment 16 and serves to cool the main food storage compartment 16 in a manner to be explained more fully hereinafter. The outlet of the second evaporator 60 is. connected to an accumulator 64 which is connected tothe inlet ofthe motor-compressor unitStl by means of the usual suction or return line 62. The accumulator 64 at the outlet of the evaporator 60 serves the dual purpose of storing surplus refrigerant and as a disengaging passage whichprevents the vaporized refrigerant from sweeping slugs of liquid refrigerant into the suction line 62.

The evaporator 60 ismounted in the air flue 70 arranged in the back wall of the compartment 16 as best shown in Figures 2 and 4 of the drawing. Air enters the flue 70 through an inlet 72 arranged adjacent the lower end of the flue as shown and leaves the flue through an outlet 74 adjacent the upper portion of the compartment 16. A fan 76 is used for forcefully circulating air through the flue so as to cool the air and then discharge it forwardly adjacent the upper portion of the compartment 16. The air then flows'downwardly in thermal exchange relationship with the foods stored in the door shelves and part of the air flows between the hydrator18 and the door and some of the air shortcuts down through the main portion of the food storage compartment on its way to the return air inlet 72. By virtue of this forced air circulation arrangement and by virtue of the fact that the food shelves and hydrator are constructed so as to facilitate the circulation of Thefan-76. is offset from the bottom of the evaporator 60 so as to be out of the path of defrost water draining from the evaporator 60 as best shown in Figure 4. The lower end of the flue and the blower extend into the compartment 16 as best shown in Figure 2 so as to allow space for insulation between the rear of the blower assembly and the outer shell 22. 7 a

The control for the motor-compressor unit consists of a thermostatic bulb 80 mounted on the upper end of the evaporator 60 as shown. This bulb operates a switch 82 (Figure 4) arranged in the circuit 83 lead ing to the motor-compressor unit 50 so as to start and stop the unit 50 in accordance with temperatures on the evaporator 60. The switch 82 is preferably set to stop the operation of the motor-compressor unit when the temperature at the bulb 80 drops down to 2 F. and restarts the compressor when the temperature at the bulb 80 reaches a value of somewhere between 34 and 36 F. By virtue of this type of a control and the refrigerant circuit arrangement shown together with the proportions of the evaporators to the sizes of the compartments to be cooled, it is possible to maintain the desired temperature differential between the frozen food compartment 14 and the food compartment 16 at all times and to cause the evaporator 60 to defrost itself duringeach oifcycle without melting any of the frozen foods.

The switch 82 includes the usual cold control adjustment 84 which enables one to adjust the setting of the switch 82 so as to maintain either colder or Warmer temperatures in accordance with well known practice.

The frozen food compartment 14 is provided with an inner door 90 which prevents the free circulation of air between the compartments 14 and 16 and which prevents air from entering the frozen food compartment 14 each time the door 20 is opened. The compartment 14 is provided with the usual ice tray shelves 92 which serve to support ice trays 94. The evaporator 56 is large enough in proportion to the 'size of the compartment 14 so as tomaintain the temperatures in the compartment 14 at or near F. with the result that water may be frozen in the trays as needed.

Since the evaporator 56 is the first to receive any liquid refrigerant it is obvious that the frozen food compartment will be maintained properly refrigerated at all times before any of the surplus refrigerant will flow upwardly into the second evaporator 60. It is also obvious that when the compressor stops operating, the refrigerant in the evaporator 60 can drain down into the first evaporator portion 56 so as; to continue refrigerating the frozen food compartment after the last of the refrigerant has been vaporized in the evaporator 60.

When no more refrigerant is left in the evaporator 6t) the air flowing over the evaporator will rather quickly raise the temperature of the evaporator above the freezing point of the frost on the evaporator so as to thereby cause defrosting of the same. The defrost water drains from the bottom of the flue 70 through a slot 95 into the bottom portion of the food compartment 16 from whence it enters a drain 100 which conveys the condensate water down into a pan 102 arranged in thermal exchange relationship with the relatively hot condenser 52 so as to cause vaporization of the defrost water. The drain 100 includes a drain tube 104 which by-passes the freezer compartment 14 and the insulation surrounding thecompartment 14.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. In a refrigerator, a cabinet having a first compartment for the storage of frozen foods and a second cornpartment above said first compartment for the .storage of unfrozen foods, said cabinet having a door for closing said second compartment, a first evaporator in said first compartment, a second evaporator constituting the compartment 5 mounted.

' sole evaporator for cooling air for said second compartment, refrigerant liquefying means, refrigerant flow connections between said refrigerant liquefying means and said first and second evaporators, hydrator means, means for supporting said hydrator means on said door in spaced relationship thereto so as to form an air passage between said hydrator means and said door, and fan means for forcefully circulating air from said second compartment into thermal exchange relationship with said second evaporator and thereafter through said air passage.

2. In a refrigerator, a cabinet having a first compartment for the storage of frozen foods and a second compartment above said first compartment for the storage of unfrozen foods, said cabinet having a single door for closing both of said compartments, a first evaporator in said first compartment, a second evaporator for cooling air for said second compartment, refrigerant liquefying means, refrigerant flow connections between said refrigerant liquefying means and said first and second evaporators, hydrator means, means for supporting said hydrator means on said door in spaced relationship thereto so as to form an air passage between said hydrator means and said door, and fan means for forcefully circulating air from said sec-ond compartment into thermal exchange relationship with said second evaporator and thereafter through said air passage, said cabinet including a flue adjacent'the rear wall of said second in which said second evaporator is 3. In a refrigerator, a cabinet having a first compartment for the storage of frozen foods and a second compartment for the storage of unfrozen foods, said cabinet having a door, a first evaporator in said first compartment, a second evaporator for cooling air for said second' compartment, refrigerant liquefying means, refrigerant flow connections between said refrigerant liquefying means and said first and second evaporators, hydrator means, means for supporting said hydrator means on said door in spaced relationship thereto so as to form an air passage between said hydrator means and said I door, fan means for forcefully circulating air from said second compartment into thermal exchange relationship with said second evaporator and thereafter through said air passage, said cabinet including a flue adjacent one wall of said second compartment in which said second evaporator is mounted, and means responsive to the temperature of said second evaporator for starting and stopping the operation of said refrigerant liquefying means.

4. In a refrigerator, a cabinet having a first compartment for the storage of. frozen foods and a second compartment above said first compartment for the storage of unfrozen foods, said cabinet having a door for closing said second compartment, a first evaporator in said first compartment, a second evaporator constituting the sole evaporator for cooling air for said second compartment, refrigerant liquefying means, refrigerant flow connections between said refrigerant liquefying means and said first and second evaporators, hydrator means, means for supporting said hydrator means on said door, and fan means for forcefully circulating air from said second compartment into thermal exchange relationship with said second evaporator and thereafter in thermal exchange relationship with said hydrator.

5. In a refrigerator, a cabinet having a compartment for the storage of unfrozen foods, means forming an air fine in one wall of said compartment, an evaporator in said air flue, refrigerant liquefying means connected to said evaporator for supplying liquid refrigerant to said evaporator, control means starting and stopping said refrigerant liquefying means in response to refrigeration requirements, said last named means including means for preventing restarting of said refrigerant liquefying means until all frost thereon has melted, fan means for circulating air upwardly through said flue, said fan means 5 being offset from the lower end of said evaporator so 2,065,604 as to be out of the path of defrost water leaving said 2,085,346 'evaporator, means for discharging said Water from the 2,122,501 lower end of said air flue onto the bottom wall of said 2,167,442 food storage compartment, and means for draining said 5 2,440,628 water from said bottom Wall and for discharging the 2,481,616 same into thermal exchange relationship with a portion 2,484,588 of said refrigerant liquefying means so as to revaporize 2,513,675 said water. 2,578,906 10 2,589,551 References Cited in the file of this patent UNITED STATES PATENTS 2,692,482 1,990,431 Frederick Feb. 5, 1935 2,712,733 2,012,262 Forsthoefel Aug. 27, 1935 15 2,740,266

6 Miller Dec. 29, Vretman June 29, Thomas July 5, Alsing July 25, Bauman Apr. 27, Richard Sept. 13, Richard Oct. 11, Quillen July 4, Tobey Dec. 18, Iwashita Mar. 18, Grimshaw Dec. 23, Bently Jan. 27, Shoemaker Oct. 26, King July 12,

Kesling Apr. 3, 

